powerpc/oops: Use IS_ENABLED() for oops markers

Just because it looks less gross.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/traps.c

@@ -208,17 +208,18 @@ static int __die(const char *str, struct pt_regs *regs, long err)
 	else
 		printk("BE ");
 
-#ifdef CONFIG_PREEMPT
+	if (IS_ENABLED(CONFIG_PREEMPT))
 		pr_cont("PREEMPT ");
-#endif
-#ifdef CONFIG_SMP
+
+	if (IS_ENABLED(CONFIG_SMP))
 		pr_cont("SMP NR_CPUS=%d ", NR_CPUS);
-#endif
+
 	if (debug_pagealloc_enabled())
 		pr_cont("DEBUG_PAGEALLOC ");
-#ifdef CONFIG_NUMA
+
+	if (IS_ENABLED(CONFIG_NUMA))
 		pr_cont("NUMA ");
-#endif
+
 	pr_cont("%s\n", ppc_md.name ? ppc_md.name : "");
 
 	if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)